HPCC-8418 Schema generation should ignore xpaths that are too long

Currently ECL generated XML schemas don't match ECL output when the xpath is longer than needed for a particular element.  I.e. no '/'s for a field, only 1 '/' for a set or dataset.

These XPATHS are used for input record structures but ignored on output.

Schema generation will now ignore these xpaths, matching output.

Signed-off-by: Anthony Fishbeck <Anthony.Fishbeck@lexisnexis.com>